1. Field of the Invention
This invention relates to a technique for reporting faults of a base station of a digital cellular system to an upper base station management unit. Specifically, this invention is a technique for reporting the faults of the base station with a message whose length is reduced.
2. Description of the Related Art
A digital cellular system, which is a code division multiple access communication system, is composed of a base station subsystem (BSS), a mobile switching center (MSC), and a home location register (HLR). A BSS consists of a base station management unit (BSM), multiple base station controllers (BSC), and multiple base station transceiver subsystems (BTS).
The system contains one BSM which is composed of work stations. BSM loads a call control processor (CCP). The BBS is equipped with a maximum of twelve CCPs. One CCP can load a maximum of thirty-two selector interface processors (SIP) and a maximum of sixteen BTS control processors (BCP). The BSS is equipped with a maximum of three hundred eighty four SIPs. One SIP can load a maximum of four selector vocoder processors (SVP). The BSS is equipped with a maximum of one hundred ninety two BCPs. One PCP loads a maximum of twenty four control interworking processors (CIP), one BTS test processor (BTP), six pairs of transceiver interface processors (TIP), and one pair of time and frequency processors (TFP).
Each BTS of the digital cellular system has a function of reporting the faults of its own devices to the BSM. There are 130 kinds of faults which can occur in a BTS. There are 11280 kinds of faults, when considering which device has what kind of a fault. The number of devices where 120 kinds of faults can occur is 30. The number of devices where the remaining 10 kinds of faults can occur is 768. Therefore, the following formula is established. 120.times.30+10.times.768=11280. The numbers 120 and 10 indicate the number of kinds of faults, and numbers 30 and 768 indicate the number of devices which are called locations.
A fault message which the BTS sends to the BSM is composed of 9 bytes. Four bytes of nine bytes indicate a kind of the fault, and another four bytes indicate a location. The remaining one byte indicates a state of a fault. When it is assumed that all cases of the faults which can occur in one BTS occur, a total length of the fault messages sent to the BSM is 101520 bytes (812160 bits). That is, 9.times.11280=101520.
This messages indicating faults of the BTS cannot all be sent to the BSM at one time because the length of the messages is limited to 128 bytes when the BTS communicates with BSM, and the data area is limited to 112 bytes. Therefore, when it is assumed that all cases of the faults which can .occur in one BTS occur, the BTS must send the messages to the BSM about 907 (=101520/112) times. It takes a long time to inform the BSM of faults of the BTS so that it also takes a long time to process the faults.
The following patents each disclose features in common with the present invention but do not teach or suggest the specifically recited technique for reporting faults of the base station with a reduced message length as in the present invention.
U.S. Pat. No. 5,513,189 to Savage, entitled Boundary Scan System With Improved Error Reporting Using Sentinel Bit Patterns, U.S. Pat. No. 5,528,516 to Yemini et al., entitled Apparatus And Method For Event Correlation And Problem Reporting, U.S. Pat. No. 5,351,247 to Dow et al., entitled Fault Identification System, U.S. Pat. No. 5,500,944 to Yoshida, entitled Fault Indication System In A Centralized Monitoring System, U.S. Pat. No. 5,481,539 to Hershey et al., entitled Datagram Communication Service Over A Cellular Telephone Network, U.S. Pat. No. 5,454,024 to Lebowitz, entitled Cellular Digital Packet Data (CDPD) Network Transmission System Incorporating Cellular Link Integrity Monitoring, and U.S. Pat. No. 5,621,753 to Weber, entitled Digital Communication System And A Primary Station For Use In Such A System.